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(NoModelj D. FIELD.

ELEGTRIG ELBVATOR.

No. 275,179. Patented Apr. 3, 1883.

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UNITED STATES PATENT OFFICE.

STEPHEN D. FIELD, OF NEV YORK, N. Y.

ELECTRIC ELEVATOR.

SPECIFICATION forming part of Letters Patent No. 275,179, dated April 3, 1883.

Application filed November 16, 1882.

(No model.)

To all whom it may concern Be it known that I, STEPHEN D. Fiano, a citizen of the United States, and a resident of the city, county, and State of New York, have invented certain new and useful Improvements in Electric Elevators, of which the following' is a specication.

My invention relates to a method of and apparatus for raising and lowering elevatorcars by means of an electro-dynamic motor, and ot' controlling and regulating the action or" the latter from a point within the car.

The accompanying drawing is a sectional view of an elevator-shaft, with its movable car and electromotor for operating the same, the

y circuit-connections being shown in diagram.,

In the drawing, A represents the elevatorcar, which is of the usual construction, and is movable up and down within a vertical inclosing-shaft, B, being suspended from above by one or more iiexible ropes, O, attached to the top of the car and passing over pulleys c o at the top ot' the shaft. rlhc opposite end of the rope or ropes C is attached to a windingdrum, D, mounted upon the axis ot' atoothed wheel, d, which in turn engages with a pinion upon the axis j' of the rotating armature of an electromotor, F. This electromotor may be of any well-known or suitable construction, and may be placed in the basement ot' the structure containing the elevator, or upon any ofthe upper iloors, the particular location in this respect being wholly immaterial. I have preferred to illustrate itin the present instance as being placed in the basement.

E represents an electric generator of any suitable character, preferably a dynamo-electric machine, which may be located at any convenient point either within or without the building in which the elevator is situated, and may even be situated at a considerable distance therefrom, an electric connection being established between the two by wires or conductors to and to', extending from the generator E to the point where the motor F is situated. The terminals l and 2 ofthe motor are preferably in permanent connection with the wires w and w', leading respectively from the positive and negative poles of the generator E.

Gis a circuit-changer, which is pivoted at g to a stationary support in any convenient position, and provided with a metallic contactarm, g', which latter is movable overa series of metallic contacts/it?, and i3, these being so disposed with reference to each other that when the arm g passes from one of them to another an electric circuit will be closed through the second before contact with the first is interrupted, and vice versa. The circuit-changer Gr is also provided with two lever-arms, h h', to which are attached the respective ends 7L h of a controlling-rope, H. This. passes from the arm h over a pulley, 11,3, and vertically upward, passing through the interior ot' the movable car A, thence overa pulley, h4, at the top ot' the shaft D, returning vertically through the shaft, preferably outside the car A, and over a pulley similar to h3 to the opposite arm ot' the lever It. A train ot' multiplying-gearing, D', engages with the toothed wheel d on the axis otA the drum D, and terminates in a small but rapidly-moving drinn, d. hen the apparatus is at rest the drinn D is held in check by the friction of a brake, H, which is mounted on the end of a lever, h2, projecting from the circuit-changer Gr.

rlhe terminals land 2 of the electromotor F are, when the apparatus is in its normal position of rest, united by a sh unt-conductor, Ss', extending from the terminal l to the circuitchanger G, thence through the arm g', contact i', and conductor s to the point 2. The second contact, fig, is united with the terminal 2 of the motor F by a conductor, 1 i, in which is'included an adjustable rheostat or artiiicial resistance, R, ot any well-known or suitable constructiona The operation ot' the apparatusis as follows: Assuming the machinery to be in its normal position ot' rest, a constantcnrrentot'electricity from the generator E passes over the wire to to the terminal l of the electromotor F, and thence over the shunt-conductor s, circuitchanger g', and conductor s to the termina-l 2, and thence by the conductor w to the positive pole ofthe generator. Inasmuch as the resistance ot' the shunt-conductor s s' between the points l and 2 is inappreciable, no appreciable current passes through the electromotor IOO from thcpoint l tothe point 2. The tendency oi' the car A is therefore to descend by the action of gravity, and thereby to turn the motor F in a reverse direction g but this tendency is checked by the action of the frictionbrake H upon the drum d', so that the appa-- ratus remains immovable. When a person entering the car A desires to cause the same to ascend, he grasps the controlling-rope h and pulls the same downward, which movement acts upon the arms iz. h' of the circuit-changer G and shifts it to the position indicated by the dotted lines. In this position the shunt-circuits s is interrupted, and the full power of the electric current from the generator E is at once exerted upon the electromotor F, causing the same to revolve rapidly in the direction indicated by the arrow, thus winding the rope C upon the drum D, and accordingly raisingthe elevator-car toward the top of the shaft in the usual manner. The car may be stopped by the person riding within it at any desired point by reversing the operation last described and restoring` the parts to the position shown in the drawing, in which case the electric current is shunted around and withdrawn from the motor F, while the brake H is si multaneously applied to the drum d', thus holding` the motor in check. When, on the other hand, it is desired to cause the car to descend,the arm g of the circuit-changer is placed upon the intermediate contact, t2, by a proper manipulation of the controlling-rope h. in this position ot the circuit-changer G the brake H is removed from the drum d', while the shunt,which spans the electromotor F, is completed through the conductors s and o', thus including the ad-v justable artificial resistance lt. Under these circumstances the descent ofthe car by gravity will rotate the electromotor F in a reverse direction, thus in eftect converting it into a dynamo-electric generator, the poles of which are connected by a shunt.

If the shunt is of very small electrical re sistance, the mechanical resistance offered by the motor will, as is well known, be very considerable, and hence the car must necessarily descend very slowly; but by increasing the resistance of the rheostat it the descent will become more rapid. rifhe rheostat R should therefore be so adjusted that the de! scent of the car will be effected at a desirable and convenient rate of speed, according to the circumstances of the particular case. By shifting the circuit-changer G so as to bring the brake H in contact with the drum d the descent may be arrested at any desired point, as hereinbeforc explained.

Two or more shunts of different rcsistances may be employed in place of the shunt 1* r', each having its independent plate for making contact with the arm g'.

i claim as my inventionil. The combination, substantially as hereinbefore set forth, of an electric generator, an

elevator-car, an electromotor actuated by a current from said generator for propelling said car against the action ot' gravity, and a circuit' changer for diverting the current of the generator away from the motor and simultaneously closing a shunt uniting the terminals of said motor for retardin g its reverse movement.

2. rEhe combination, substantially as hereinbefore set forth, of au electric generator, an elevator-car, an electromotor actuated by a current from said generator for propelling said car against the action of gravity, a circuitchanger for diverting the current of the generator away from the motor and simultaneously closing a shunt uniting the terminals of said motor for the purpose ot' retarding its reverse movement, and means for actuating said circuit-changer from a point within the Inovable car.

3. rihe combination, substantially as hereinbefore set forth, of an electric generator, an elevator-car, an electromotor actuated by a current from said generator for propelling said car against the action of gravity, a shunt spanning said electromotor for retarding its reverse motion under the action of gravity, and a switch or circuit-changer for opening and closing said shunt.

et. The combination, substantially as hereinbefore set forth, of an electric generator, an elevator-car, an electromotor actuated by a current from said generator for propelling said car against the action of gravity, ashunt spanning said electromotor for retarding its reverse motion under the action of gravity, a switch or circuit-changer for opening and closing said shunt, and an artificial resistance included in said shunt.

5. The combination, substantially as hereinbefore set forth, of an electric generator, an elevatorcar, an electromotor actuated by a current from said generator for propelling said car against the action of gravity, a shunt spanning said electromotor for retarding its reverse motion under the action of gravity, a switch or circuitchanger for opening and closing said shunt, and an adjustable or variable artificial resistance included in said shunt.

6. Themcombination, substantially as hereinbefore set forth, of an electric generator, an elevator-car, an electromotor actuated by a current from said generator for propelling said car against the action of gravity, a shunt spanning said electromotor for retarding its reverse motion under the action of gravity, a circuit-changer or switch foropening and closing said shunt, and a friction-brake orstop for arresting the motion of the motor.

T. The combination,substantially as hereinbcfore set forth, of an electric generator, an elevator-car, an electromotor actuated by a current from said generator for propelling said car against the action of gravity, a shunt IOO IOS

IIO

spanning said electromotor for retarding its In testimony whereof I have hereunto subreverse motion under the action of gravity, a scribed my name this 15th day of November, circuit-changer or switch for opening or clos- A. D. 1882.

ing said shunt, a friction brake or stop for ar- STEPHEN D. FIELD. 5 resting the motion of the motor, and means Witnesses:

for actuating said circuitchanger and brake i DANIEL W. EDGECOMB,

from a point within the car. CHARLES A. TERRY. 

